#include <REGX52.H>
void Delay(unsigned int xms)
{
	unsigned char i, j;
	while(xms)
	{
			i = 2;
			j = 239;
			do
		{
			while (--j);
		} while (--i);
		xms--;
	}
	
	
}

void main()
{
	
	while(1)
	{
		if(P3_1==0)
		{
			Delay(20);
			while(P3_1==0);
			Delay(20);
			
			P2_0 = ~P2_0;
		}
	}
}